Lowering mechanism applicable for use in portable life-saving apparatus



June 3, 1930. J. D. REDMOND 1,761,311

LOWERING MECHANISM APPLICABLE FOR USE IN PORTABLE LIFE SAVING APPARATUSFiled March 10, 1927 3 Sheets-Sheet l Ill/[Ill I INVENTOR: 46 JAMES D.REDMOND,

W BY his Attorn s,

June 3, 1930. J REDMOND 1,761,311

LOWERING MECHANISM APPLICABLE FOR USE IN PORTABLE LIFE SAVING APPARATUSFiled March 10. 1927 3 Sheets-Sheet '2 June 3, 1930. J. D. REDMOND1,751,311

I LOWERING MECHANISM APPLICABLE FOR USE IN PORTABLE LIFE SAVINGAPPARATUS Filed March 10, 1927 3 Sheets-Sheet 5 Patented June 3, 1930UNITED STATES PATENT OFFICE JAMES DERMOT REDMOND, OF EARLSWOOD, ENGLANDApplication filed March 10,1927, Serial No. 174,223, and in GreatBritain March 16, 1926.

provide a portable fire escape in which means are. provided whereby theoperator during his descent from a building can control the speed atwhich he is lowered.

In one form of construction a portable fire escape comprises a frame inwhich is rotat-- ably mounted a drum adapted to receive a cable. Thedrum forms a liquid container and means are provided in the drum wherebythe liquid is caused to flow backwards and forwards from one part of thecontainer to another when the drum is rotated. Means are providedwhereby the frame is attached to the operator. There is also providedmeans 2o operable by the operator during his descent for controlling therate of flow of the liquid in the container. Means are preferablyprovided for governing the rate of retardation of the flow of the liquidand means may be provided for rotating the drum in order to rewind anycable which has been paid out from the drum.

The invention is illustrated in the accompanying drawings, in whichFigure 1 is a vertical section through one form of theapparatus; Figure2 is a fragmentary elevation of the control or operating parts of saidform; Figure 3 is a detail sectional view taken on the line 33 of Figure1; Figure 3 is a View similar to Figure 1 taken through a modified form;Figure 4 is a side elevation of a modified form of control handle;Figures 5 and 6 are detail views of the handle, Figure 7 is analternative form of spindle and Figure 8 a diagrammatic view of thecomplete apparatus. a

In the construction shown in Figures 1 to 3. a drum 1, convenientlyprovided with a helical groove 2 to receive a cable 2, is rotatablymounted upon disks i of a bearing at which'is fast with a'casing orframe t and carries a central tube or hollow shaft 3 forming a valvechamber.

The sides of the drum 1 are provided wlth interior cam projections 5,which engage a diaphragm 6 slidably but non-rotatably mounted on thecentral tube 3 and cause the said diaphragm to reciprocate when the drumis rotated.

In this construction the drum itself constitutes the liquid container.The tube 3 is provided with ports 7, 8, through which the liquid isforced by the movement of said diaphragm 6 from one side to the other ofthe container. Means for automatically governing or retarding the flowof the liquid are located inside the tube, and comprise. one ormoresprings 9 located over passages 8 of a diametric partition 9 in tube 8,so arranged that on increase of speed of rotation of the drum, andconsequent increase in the rate of flow of the liquid, at least one ofsaid springs is moved by the pressure of the liquid partially to closeone of the passages 8, thereby checking the flow of the liquid andconsequently preventing the speed of rotation of the drum from undulyincreasing.

The casing 4 is provided with a strap 46 shown in Figures 1 and 8.

The cable may be attached to a suitable piece of furniture and theperson to be lowered fastens the body strap 46 in position about hisbody and lowers himself from the building. On rotation of the drum, dueto the weight of the body being lowered, the diaphragm 61noves axiallybackwards and forwards along the tube 3, owing to the cam projections 5on the inner face of the drum. the liquid in the container being therebyforced'to flow alternately through the ports 7 and 8 in the tube 3 andthrough passages 8. Preferably the liquid employed is an oil having ahigh degree of viscosity.

On increase of speed of rotation of the drum, and consequent increase inthe rate of flow of liquid, the pressure of liquid in the tube acts onone or more of the springs 9 and bends same toward the coacting passages8" thus partially closing the latter passages 8 for the liquid henceregulating the flow of the liquid. Adjacent the springs 9 are arrangedshields 9 which direct the liquid 011 to the springs 9.

The normal rate of flow of the liquid and consequently the speed ofrotation of the drum 1 is governed by means of a diaphragm 10 fast onthe tube 3, and a plate 11 fast on a spindle 3 which is journaled in thebearing 4 for limited rotation independently of and relatively to tube3. The diaphragm and plate are provided with one or more ports 12 and12, respectively, which can be moved more or less into and out ofregistration with one another through rotation of the spindle 3.

Fastened on the spindle 3 is a manually operable disk 13 having aneccentric 14 which is partly embraced by an arcuate spring 15, one endof which is secured to a pin 15 fast in the bearing 4, the springtending always to return the disk to its normal position as in FigureThe disk is provided with an abutment 13 which engages in the normalposi tion, a stop 16 on an actuating lever or handle 17 fast on thebearing 4. The openings of the ports 12' can be varied by rotating thedisk 13 and; thus the rate of flow of the liquid is controlled.

The bearing 4 is not fast with the casing or frame 4, but is normallyconnected thereto by conventional pawls 19 on the frame 4. Said pawl'sengage ratchet depressions or teeth 20 on the drum bearing disks 4.\Vhen the cable is running out, the drum rotates freely on its bearings,but on rewinding, the initial movement of the handle 17 throughengagement of lugs 16 and 13, slightly rotates disk 13 to the extentpermitted by cam 14 and spring 15, thus moving port 12 out of registerywith the ports 12 which partly or completely closes the latter ports.Further movement of the handle 17 rotates the hearing 4 and diaphragm 6and since the area, of the ports 12 is small, the drive is transmittedthrough the liquid to the drum, the pawls 19 riding over the ratchetdepressions 20.

In operation, when cable 2 is fastened to furniture,- or the like,,andstrap 4Gis secured to the body, the apparatus is used to control thedescent of the person, the .tube 3, bearing 4 and handle 17 fasttherewith are held from rotation by the engagement of pawls 19 with theratchet depressions 20, the drum 1 rotating on the bearing disks 4. Ifthe person desires to vary his rate of descent, he manually rotates thedisk 13in a clockwise direction and hence the spindle 3. and disk 11 isrotated with respect to the bearing 4. Immediately upon release of thedisk 13, it is urged back to its normal position where lug 13 and lug 16engage, by the action of the spring 15. During rewinding, the lug 13 ismaintained in engagement with the lug 16 by the spring 15 and eccentric14, and due tothis engagement, the disk 11 is rotated at the same speed.as the disk 10, and thus the same normal relative position is maintainedbetween the disks 10 and. 11.

Referring to the modified form. of Figure most of the parts are similarto those previously described and in such instances, bear the samereference characters. The bearing 4, however, is rigidly fixed at 4 tothe casing 4. A diaphragm 10 is fixed in tube 3 and has a passage 1Otherethrough so that the liquid may travel through ports 8, 8, 10 and 7and vice versa, under control of spring valves 9. This form of theinvention omits the descent-regulating control consisting of valve plate11 and associated parts of the preceding form.

In the modified form of control handle shown in Figures 4, 5 and 6, theoperating handle or lever 17 primarily supplants handle 17 and disk 13of Figures 1 to 3 and is loosely mounted on the drum bearing 4equivalent to that at 4 in the preceding ligures, and is provided withshoulders 22 which are adapted to engage shoulders 23 on the drumhearing. A handle 17 pivotally mounted on the lever is provided withratchet teeth 24 which engage a spring operated pawl 25 carried by thelever. On the pawl 25 is a projection 27 which may be engaged by a camsurface 28 on the frame 4, the cam be ing so arranged as to withdraw thepawl from the ratchet only when the lever is in a central verticalposition, in which position the ports 12 and 12 are in their normalsetting, that is, in full registry. In said normal setting the ports areso designed that a person of normal weight will be lowered at a saferate.

The handle is provided with two projections 29,-to which are pivotedlinks 30, to which latter is pivoted a finger 31 pressed into operationby a spring 32, which is compressed when the handle is turned down. Thefinger 31 when the handle 17 is in its raised (i. e. inoperative)position contacts with a pin 33 in the frame 4 and pushes it (againstthe action of a spring 33) into engagement with a hole 34 in the drumbearing. Bearing against the finger 31 is a spring 35 which normallytends to press the finger into engagement with the pin 33, but allowsthe handle to be returned to its inoperative position, even when the pinis not in engagement with thehole 34.

Fast on the lever 17 is a projection 36, engaging with one arm 37 of athree-armed spider, which is fast on the spindle 3. Attachedto theremaining arms of the spider are two springs 38, fastened at their otherends to a boss 38 on the bearing 4, and which normally tend to maintainthe ports 12 and 12 at their normal setting or in full registry.

In operation, the ports are normally controlled by moving the lever 17to the extent controlled by the shoulders 22, 23. hen it is desired torewind the drum, the lever 17 is first moved to the position in whichthe ports are closed. Movement of the handle 17, which is permitted bythe pawl 25 running over the ratchet teeth 24, automatioally allows thewithdrawal of the pin 33 by means of the links 30, thus allowing thebearing et to rotate relatively to the frame 4.

Referring now to Figure 7, the tube 3 is divided into two portions by apartition 39, provided with ports 40. A second partition 41 is providedat right angles to the first hav ing a port 42. Carried by the partition39 are springs l3 which are acted upon by the pressure of the liquid andare flattened out so as partially to overlap the ports 40. In thepartition 39 are two by-passes 44, by means of which a liquid cushioneffect is imparted to the springs. Shields 45 are also provided, as inthe construction shown in Figures 1 to IVhat I claim is 1. In a portablefire escape, the combination of a frame, a drum rotatably mountedtherein to contain a liquid and adapted to receive a cable, meanswhereby the liquid in the drum is caused to flow backwards and forwardsfrom one part of the drum to another when the drum is rotated, means forattaching the frame to the operator and means operable by the operatorduring his descent for controlling the rate of flow of said liquid.

2. In a portable fire escape, the combinationof a frame, a drumrotatably mounted therein adapted to "contain a liquid and to receive acable, said drum having a passage adapted to allow liquid to flow fromone part of the drum to another, means whereby the liquid in the drum iscaused to flow backwards and forwards from one part of the drum toanother, through said passage when the drum is rotated, means forattaching the frame to the body of a user, and means for automaticallyvarying the effective cross sectional area of the passage in accordancewith variations in weight of different users.

3. In a portable fire escape, the combinaof a frame, a drum rotatablymounted there .in to contain a liquid and adapted to receive a cable,means whereby the liquid in the drum is caused to flow backwards andforwards from one part of the drum to another when the drum is rotated,means for attaching the frame to the operator, means for automaticallycontrolling the rate of flow of said l quid and means operable by theoperator during his descent for controlling the rate of flow of saidliquid.

at. In a portable lire escape, the combination of a frame, a drumrotatably mounted therein to contain a liquid and adapted to rereceiveacable, a central shaft, a diaphragm slidably mounted on said centralshaft, internal cam projections on the drum --Wl1lCl1 engage saiddiaphragm so as to cause the liquid in the drum to flow backwards andforwards from one part of the drum to another whcn the drum is rotated,means for attaching the frame 'to the operator and means operable by theoperator during his descent for controlling the rate of flow of saidliquid. 1

5. In a portable fire escape, the combination of a frame, a drumrotatably mounted therein and adapted to receive a cable and to containa liquid, a hollow central tube for the drum forming a valve chamber,means whereby the liquid in the drum is caused to flow from one part ofthe drum to another when the drum is rotated, means for attaching. theframe to the operator, and means opei able by the operator during hisdescent for controlling the rate of flow of said liquid.

6. In a portable fire escape as claimed in claim 5 means for normallypreventing the hollow central tube from rotating and means which allowsit to rotate when the drum is being rewound. r

7 In a portable fire escape, the combination of a frame, a drumrotatably mounted therein to contain a liquid and adapted to receive acable, a hollow central shaft forming a valve chamber, a diaphragmslidably mounted on said central shaft, internal cam projections on thedrum which engage said diaphragm so as to cause the liquid in the drumto flow backwards and forwards from one part of the drum to another whenthe drum is rotated, means which allows the hollow shaft to rotate whenthe drum is being rewound, a rewinding handle, movement of which intoits operative position automatically permits rotation between the hollowcentral shaft and the frame, means for attaching the frame to theoperator and means operable by the operator during his descent forcontrolling the rate of flow of said liquid.

8. A portable fire escape as claimed in claim 5 in which the centraltube is provided with ports adapted to restrict the flow of liquid.

9. In a portable fire escape, the combination of a frame, a drumrotatably mounted therein to contain a liquid and adapted to receive acable, a hollow central shaft forn1- ing a valve chamber, a diaphragmslidably mounted on the said shaft, internal cafii projections on thedrum and which engage said diaphragm so as to cause the liquid in thedrum to flow backwards and forwards from one part of the drum to theother when the drum is rotated, ports in the hollow central shaft,spring actuated means subjected to the action of the liquid to controlthe effective. areas of the ports, means for attaching the frame to theoperator and means operable bv the operator during his descent forcontrol ling the rate of flow of said liquid.

10. In a portable fire escape, the combination of a frame, a drumrotatably mounted therein to contain a liquid and adapted to receive acable, a hollow central shaft forming a valve chamber, a diaphragmslidably mounted on said central shaft, internal cam projections on thedrum Which engage said diaphragm so as to cause the liquid in thecontainer to flow backwards and forwards I from one part of the drum toanother when the drum is rotated, means for preventing the said shaftfrom rotating except when the drum is being rewound, a rewinding handle,movement of which into its operative posi- 10 tion automatically permitsrotation between the hollow central shaft and the frame and alsoprevents the flow of liquid, means for attaching the frame to theoperator and means operable by the operator during his 15 descent forcontrolling the rate of flow of said liquid.

In testimony that I claim the foregoing as my invention I have signed myname this 1st day of March, 1927.

20 JAMES DERMOT REDMOND.

